Connect an MCP client

Same endpoint for all clients. JSON shape differs slightly for VS Code.

Keep onlinesim mcp running while the client is connected.

Auto-wire (recommended)

Write the HTTP endpoint into IDE config files. Does not start the MCP server.

Bash

onlinesim mcp install
onlinesim mcp install --client cursor --global
onlinesim mcp install --client vscode --project
onlinesim mcp install --client claude --project
onlinesim mcp install --client all --project
onlinesim mcp install --client codex --global

Flags: --dir <project>, --url <endpoint>, --force (overwrite existing onlinesim entry).

Cursor

Put this JSON in a Cursor mcp.json file:

~/.cursor/mcp.json — global (all projects)
.cursor/mcp.json — this project

JSON

{
  "mcpServers": {
    "onlinesim": {
      "type": "http",
      "url": "http://127.0.0.1:8787/mcp"
    }
  }
}

Claude Code

Claude Code CLI scopes:

Bash

claude mcp add --scope user --transport http onlinesim http://127.0.0.1:8787/mcp
claude mcp add --scope project --transport http onlinesim http://127.0.0.1:8787/mcp

Or use a project file (same JSON as Cursor): .mcp.json

VS Code

Project file .vscode/mcp.json — key is servers (not mcpServers):

JSON

{
  "servers": {
    "onlinesim": {
      "type": "http",
      "url": "http://127.0.0.1:8787/mcp"
    }
  }
}

Codex

Bash

codex mcp add onlinesim --url http://127.0.0.1:8787/mcp

Or set url under [mcp_servers.onlinesim] in ~/.codex/config.toml.

Claude Desktop

Local HTTP needs a bridge:

Bash

npx -y mcp-remote http://127.0.0.1:8787/mcp --transport http-only